Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Expose sched_yield on non-linux-like hosts #1090

Merged
merged 3 commits into from
Jul 3, 2019
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions CHANGELOG.md
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
([#928](https://github.com/nix-rust/nix/pull/928))

### Fixed
- Enabled `sched_yield` for all nix hosts.
([#1090](https://github.com/nix-rust/nix/pull/1090))

### Removed

## [0.14.1] - 2019-06-06
Expand Down
2 changes: 0 additions & 2 deletions src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -62,8 +62,6 @@ pub mod net;
pub mod poll;
#[deny(missing_docs)]
pub mod pty;
#[cfg(any(target_os = "android",
target_os = "linux"))]
pub mod sched;
pub mod sys;
// This can be implemented for other platforms as soon as libc
Expand Down
230 changes: 123 additions & 107 deletions src/sched.rs
Original file line number Diff line number Diff line change
@@ -1,131 +1,147 @@
use std::mem;
use std::os::unix::io::RawFd;
use std::option::Option;
use libc::{self, c_int, c_void};
use {Error, Result};
use errno::Errno;
use ::unistd::Pid;

// For some functions taking with a parameter of type CloneFlags,
// only a subset of these flags have an effect.
libc_bitflags!{
pub struct CloneFlags: c_int {
CLONE_VM;
CLONE_FS;
CLONE_FILES;
CLONE_SIGHAND;
CLONE_PTRACE;
CLONE_VFORK;
CLONE_PARENT;
CLONE_THREAD;
CLONE_NEWNS;
CLONE_SYSVSEM;
CLONE_SETTLS;
CLONE_PARENT_SETTID;
CLONE_CHILD_CLEARTID;
CLONE_DETACHED;
CLONE_UNTRACED;
CLONE_CHILD_SETTID;
CLONE_NEWCGROUP;
CLONE_NEWUTS;
CLONE_NEWIPC;
CLONE_NEWUSER;
CLONE_NEWPID;
CLONE_NEWNET;
CLONE_IO;
use libc;
use {Errno, Result};

#[cfg(any(target_os = "android", target_os = "linux"))]
pub use self::sched_linux_like::*;

#[cfg(any(target_os = "android", target_os = "linux"))]
mod sched_linux_like {
use errno::Errno;
use libc::{self, c_int, c_void};
use std::mem;
use std::option::Option;
use std::os::unix::io::RawFd;
use unistd::Pid;
use {Error, Result};

// For some functions taking with a parameter of type CloneFlags,
// only a subset of these flags have an effect.
libc_bitflags! {
pub struct CloneFlags: c_int {
CLONE_VM;
CLONE_FS;
CLONE_FILES;
CLONE_SIGHAND;
CLONE_PTRACE;
CLONE_VFORK;
CLONE_PARENT;
CLONE_THREAD;
CLONE_NEWNS;
CLONE_SYSVSEM;
CLONE_SETTLS;
CLONE_PARENT_SETTID;
CLONE_CHILD_CLEARTID;
CLONE_DETACHED;
CLONE_UNTRACED;
CLONE_CHILD_SETTID;
CLONE_NEWCGROUP;
CLONE_NEWUTS;
CLONE_NEWIPC;
CLONE_NEWUSER;
CLONE_NEWPID;
CLONE_NEWNET;
CLONE_IO;
}
}
}

pub type CloneCb<'a> = Box<FnMut() -> isize + 'a>;

#[repr(C)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct CpuSet {
cpu_set: libc::cpu_set_t,
}
pub type CloneCb<'a> = Box<FnMut() -> isize + 'a>;

impl CpuSet {
pub fn new() -> CpuSet {
CpuSet { cpu_set: unsafe { mem::zeroed() } }
#[repr(C)]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
pub struct CpuSet {
cpu_set: libc::cpu_set_t,
}

pub fn is_set(&self, field: usize) -> Result<bool> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_ISSET(field, &self.cpu_set) })
impl CpuSet {
pub fn new() -> CpuSet {
CpuSet {
cpu_set: unsafe { mem::zeroed() },
}
}
}

pub fn set(&mut self, field: usize) -> Result<()> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_SET(field, &mut self.cpu_set) })
pub fn is_set(&self, field: usize) -> Result<bool> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_ISSET(field, &self.cpu_set) })
}
}
}

pub fn unset(&mut self, field: usize) -> Result<()> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_CLR(field, &mut self.cpu_set) })
pub fn set(&mut self, field: usize) -> Result<()> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_SET(field, &mut self.cpu_set) })
}
}
}
}

pub fn sched_setaffinity(pid: Pid, cpuset: &CpuSet) -> Result<()> {
let res = unsafe {
libc::sched_setaffinity(pid.into(),
mem::size_of::<CpuSet>() as libc::size_t,
&cpuset.cpu_set)
};
pub fn unset(&mut self, field: usize) -> Result<()> {
if field >= 8 * mem::size_of::<libc::cpu_set_t>() {
Err(Error::Sys(Errno::EINVAL))
} else {
Ok(unsafe { libc::CPU_CLR(field, &mut self.cpu_set) })
}
}
}

Errno::result(res).map(drop)
}
pub fn sched_setaffinity(pid: Pid, cpuset: &CpuSet) -> Result<()> {
let res = unsafe {
libc::sched_setaffinity(
pid.into(),
mem::size_of::<CpuSet>() as libc::size_t,
&cpuset.cpu_set,
)
};

/// Explicitly yield the processor to other threads.
///
/// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html)
pub fn sched_yield() -> Result<()> {
let res = unsafe {
libc::sched_yield()
};
Errno::result(res).map(drop)
}

Errno::result(res).map(drop)
}
pub fn clone(
mut cb: CloneCb,
stack: &mut [u8],
flags: CloneFlags,
signal: Option<c_int>,
) -> Result<Pid> {
extern "C" fn callback(data: *mut CloneCb) -> c_int {
let cb: &mut CloneCb = unsafe { &mut *data };
(*cb)() as c_int
}

pub fn clone(mut cb: CloneCb,
stack: &mut [u8],
flags: CloneFlags,
signal: Option<c_int>)
-> Result<Pid> {
extern "C" fn callback(data: *mut CloneCb) -> c_int {
let cb: &mut CloneCb = unsafe { &mut *data };
(*cb)() as c_int
let res = unsafe {
let combined = flags.bits() | signal.unwrap_or(0);
let ptr = stack.as_mut_ptr().offset(stack.len() as isize);
let ptr_aligned = ptr.offset((ptr as usize % 16) as isize * -1);
libc::clone(
mem::transmute(
callback as extern "C" fn(*mut Box<::std::ops::FnMut() -> isize>) -> i32,
),
ptr_aligned as *mut c_void,
combined,
&mut cb as *mut _ as *mut c_void,
)
};

Errno::result(res).map(Pid::from_raw)
}

let res = unsafe {
let combined = flags.bits() | signal.unwrap_or(0);
let ptr = stack.as_mut_ptr().offset(stack.len() as isize);
let ptr_aligned = ptr.offset((ptr as usize % 16) as isize * -1);
libc::clone(mem::transmute(callback as extern "C" fn(*mut Box<::std::ops::FnMut() -> isize>) -> i32),
ptr_aligned as *mut c_void,
combined,
&mut cb as *mut _ as *mut c_void)
};

Errno::result(res).map(Pid::from_raw)
}
pub fn unshare(flags: CloneFlags) -> Result<()> {
let res = unsafe { libc::unshare(flags.bits()) };

Errno::result(res).map(drop)
}

pub fn unshare(flags: CloneFlags) -> Result<()> {
let res = unsafe { libc::unshare(flags.bits()) };
pub fn setns(fd: RawFd, nstype: CloneFlags) -> Result<()> {
let res = unsafe { libc::setns(fd, nstype.bits()) };

Errno::result(res).map(drop)
Errno::result(res).map(drop)
}
}

pub fn setns(fd: RawFd, nstype: CloneFlags) -> Result<()> {
let res = unsafe { libc::setns(fd, nstype.bits()) };
/// Explicitly yield the processor to other threads.
///
/// [Further reading](http://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html)
pub fn sched_yield() -> Result<()> {
let res = unsafe { libc::sched_yield() };

Errno::result(res).map(drop)
}